1. Field of Invention
This invention relates to electrical connectors and more particularly to a quick-connect and disconnect single point direct current connector.
A single point electrical connector for alternating current is common because of the sine wave characteristics of this type of electrical current. On the other hand, direct current has a positive current flow and a negative or ground. If these polarities are crossed, dangerous arcing can occur, particularly at higher amperages. Also, any devices that are connected with opposite polarity can be badly damaged or destroyed.
Because of the above problems with direct current, the terminals are clearly marked with "plus" and "minus" indicia as well as often being red and black color-coded. Additionally, particularly on high amperage applications such as storage batteries, fuel cells and the like, the terminals are spaced widely apart in an effort to reduce the possibility of a direct short across the terminals. This wide spacing of the terminals requires two-point connections for direct voltage applications, one connection for the positive and one connection for the negative. This is not only time consuming in connecting and disconnecting, but it also makes the system twice as expensive as alternate current connections.
Attempts have been made to improve the safety in high amperage direct current applications such as storage batteries and fuel cells. These systems have all required modification to the power sources, which makes them impractical due to the cost involved in totally redesigning such terminals. The reason for this is manufacturers must commit to production and inventory space which requires a large expenditure in capital. Distributors, retailers and vendors all must also commit to space and capital to inventory newly designed batteries and fuel cells while maintaining an inventory of conventional units. Thus there is no practical product that addresses the cross polarity danger.
2. Concise Explanation of Prior Art
U.S. Pat. No. 1,999,945 to Raymond E. Rathbum discloses a storage battery with terminal mounted in a retaining structure.
U.S. Pat. No. 4,226,497 to Samuel Polonsky and Edward V. Pomponio, assignee General Electric Company of New York, N.Y. discloses a 9-volt battery terminal with different shaped connectors so it cannot be reversed polarity mounted. Reverse polarity contact, however, can easily occur with resultant damage.
U.S. Pat. No. 4,555,451 to Lawrence R. Harrod and Lucio C. Perego, assignee Pines of America, Inc. of Fort Wayne, Ind. discloses a storage battery with a built in fuse which is good for special applications but would be very expensive to produce.
U.S. Pat. No. 4,637,965 to Ronald G. Davis, assignee H. Milton Keathley and Douglas Michael Phenix, both of Erick, Okla. discloses an anticorrosion battery terminal for wet cell automotive storage batteries.
U.S. Pat. No. 4,756,978 to Walter Nitcher discloses a battery and mount with mating contacts.
U.S. Pat. No. 4,885,524 to William M. Wilburn, assignee William J. Goldcamp of Portsmouth, Ohio discloses a specially designed vehicle battery system with a plug that can be used in conjunction with a specially designed jumper cable for the purpose of starting vehicles with bad or weak batteries.
Finally, U.S. Pat. No. 4,972,135 to Bobby l. Bates and Wesley V. Bates discloses a switching system for battery jumper cables that includes an automatic polarity-sensing circuit which prevents current from flowing until the correct polarity is connected.